The CSU550AP-3-001 is a 550 W distributed power supply housed in a compact 1U rack-mount enclosure measuring 73.5 x 185.0 mm, delivering high power density of 17 W/in³ through advanced power switching technology and high-density component packaging. The unit provides a main 12 V DC output rated for 45 A maximum current with 120 mV output ripple, plus a 12 VSB standby output rated for 2.5 A, both with regulation ranges of 11.4 V to 12.6 V. It features wide input voltage acceptance (90–264 Vac or 164–320 Vdc), 80plus Platinum efficiency, active power factor correction, and comprehensive protection including output overcurrent protection (55–62 A), overvoltage protection (13.3–14.5 V), and overtemperature/fan fault protection. The power supply supports N+M redundancy with active current sharing within ±5% at full load, PMBus compliance for digital control, and hot-pluggable operation, making it ideal for distributed power architectures in telecommunications, data center, and industrial applications requiring high reliability and space efficiency.